xref: /linux-6.15/include/linux/fsnotify.h (revision 4dc7ccf7)
1 #ifndef _LINUX_FS_NOTIFY_H
2 #define _LINUX_FS_NOTIFY_H
3 
4 /*
5  * include/linux/fsnotify.h - generic hooks for filesystem notification, to
6  * reduce in-source duplication from both dnotify and inotify.
7  *
8  * We don't compile any of this away in some complicated menagerie of ifdefs.
9  * Instead, we rely on the code inside to optimize away as needed.
10  *
11  * (C) Copyright 2005 Robert Love
12  */
13 
14 #include <linux/dnotify.h>
15 #include <linux/inotify.h>
16 #include <linux/fsnotify_backend.h>
17 #include <linux/audit.h>
18 #include <linux/slab.h>
19 
20 /*
21  * fsnotify_d_instantiate - instantiate a dentry for inode
22  * Called with dcache_lock held.
23  */
24 static inline void fsnotify_d_instantiate(struct dentry *entry,
25 						struct inode *inode)
26 {
27 	__fsnotify_d_instantiate(entry, inode);
28 
29 	inotify_d_instantiate(entry, inode);
30 }
31 
32 /* Notify this dentry's parent about a child's events. */
33 static inline void fsnotify_parent(struct dentry *dentry, __u32 mask)
34 {
35 	__fsnotify_parent(dentry, mask);
36 
37 	inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
38 }
39 
40 /*
41  * fsnotify_d_move - entry has been moved
42  * Called with dcache_lock and entry->d_lock held.
43  */
44 static inline void fsnotify_d_move(struct dentry *entry)
45 {
46 	/*
47 	 * On move we need to update entry->d_flags to indicate if the new parent
48 	 * cares about events from this entry.
49 	 */
50 	__fsnotify_update_dcache_flags(entry);
51 
52 	inotify_d_move(entry);
53 }
54 
55 /*
56  * fsnotify_link_count - inode's link count changed
57  */
58 static inline void fsnotify_link_count(struct inode *inode)
59 {
60 	inotify_inode_queue_event(inode, IN_ATTRIB, 0, NULL, NULL);
61 
62 	fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
63 }
64 
65 /*
66  * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
67  */
68 static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
69 				 const char *old_name,
70 				 int isdir, struct inode *target, struct dentry *moved)
71 {
72 	struct inode *source = moved->d_inode;
73 	u32 in_cookie = inotify_get_cookie();
74 	u32 fs_cookie = fsnotify_get_cookie();
75 	__u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
76 	__u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
77 	const char *new_name = moved->d_name.name;
78 
79 	if (old_dir == new_dir)
80 		old_dir_mask |= FS_DN_RENAME;
81 
82 	if (isdir) {
83 		isdir = IN_ISDIR;
84 		old_dir_mask |= FS_IN_ISDIR;
85 		new_dir_mask |= FS_IN_ISDIR;
86 	}
87 
88 	inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir, in_cookie, old_name,
89 				  source);
90 	inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, in_cookie, new_name,
91 				  source);
92 
93 	fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie);
94 	fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie);
95 
96 	if (target) {
97 		inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL);
98 		inotify_inode_is_dead(target);
99 
100 		/* this is really a link_count change not a removal */
101 		fsnotify_link_count(target);
102 	}
103 
104 	if (source) {
105 		inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
106 		fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
107 	}
108 	audit_inode_child(moved, new_dir);
109 }
110 
111 /*
112  * fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
113  */
114 static inline void fsnotify_inode_delete(struct inode *inode)
115 {
116 	__fsnotify_inode_delete(inode);
117 }
118 
119 /*
120  * fsnotify_nameremove - a filename was removed from a directory
121  */
122 static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
123 {
124 	__u32 mask = FS_DELETE;
125 
126 	if (isdir)
127 		mask |= FS_IN_ISDIR;
128 
129 	fsnotify_parent(dentry, mask);
130 }
131 
132 /*
133  * fsnotify_inoderemove - an inode is going away
134  */
135 static inline void fsnotify_inoderemove(struct inode *inode)
136 {
137 	inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL);
138 	inotify_inode_is_dead(inode);
139 
140 	fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
141 	__fsnotify_inode_delete(inode);
142 }
143 
144 /*
145  * fsnotify_create - 'name' was linked in
146  */
147 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
148 {
149 	inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name,
150 				  dentry->d_inode);
151 	audit_inode_child(dentry, inode);
152 
153 	fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
154 }
155 
156 /*
157  * fsnotify_link - new hardlink in 'inode' directory
158  * Note: We have to pass also the linked inode ptr as some filesystems leave
159  *   new_dentry->d_inode NULL and instantiate inode pointer later
160  */
161 static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
162 {
163 	inotify_inode_queue_event(dir, IN_CREATE, 0, new_dentry->d_name.name,
164 				  inode);
165 	fsnotify_link_count(inode);
166 	audit_inode_child(new_dentry, dir);
167 
168 	fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
169 }
170 
171 /*
172  * fsnotify_mkdir - directory 'name' was created
173  */
174 static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
175 {
176 	__u32 mask = (FS_CREATE | FS_IN_ISDIR);
177 	struct inode *d_inode = dentry->d_inode;
178 
179 	inotify_inode_queue_event(inode, mask, 0, dentry->d_name.name, d_inode);
180 	audit_inode_child(dentry, inode);
181 
182 	fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
183 }
184 
185 /*
186  * fsnotify_access - file was read
187  */
188 static inline void fsnotify_access(struct dentry *dentry)
189 {
190 	struct inode *inode = dentry->d_inode;
191 	__u32 mask = FS_ACCESS;
192 
193 	if (S_ISDIR(inode->i_mode))
194 		mask |= FS_IN_ISDIR;
195 
196 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
197 
198 	fsnotify_parent(dentry, mask);
199 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
200 }
201 
202 /*
203  * fsnotify_modify - file was modified
204  */
205 static inline void fsnotify_modify(struct dentry *dentry)
206 {
207 	struct inode *inode = dentry->d_inode;
208 	__u32 mask = FS_MODIFY;
209 
210 	if (S_ISDIR(inode->i_mode))
211 		mask |= FS_IN_ISDIR;
212 
213 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
214 
215 	fsnotify_parent(dentry, mask);
216 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
217 }
218 
219 /*
220  * fsnotify_open - file was opened
221  */
222 static inline void fsnotify_open(struct dentry *dentry)
223 {
224 	struct inode *inode = dentry->d_inode;
225 	__u32 mask = FS_OPEN;
226 
227 	if (S_ISDIR(inode->i_mode))
228 		mask |= FS_IN_ISDIR;
229 
230 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
231 
232 	fsnotify_parent(dentry, mask);
233 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
234 }
235 
236 /*
237  * fsnotify_close - file was closed
238  */
239 static inline void fsnotify_close(struct file *file)
240 {
241 	struct dentry *dentry = file->f_path.dentry;
242 	struct inode *inode = dentry->d_inode;
243 	fmode_t mode = file->f_mode;
244 	__u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
245 
246 	if (S_ISDIR(inode->i_mode))
247 		mask |= FS_IN_ISDIR;
248 
249 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
250 
251 	fsnotify_parent(dentry, mask);
252 	fsnotify(inode, mask, file, FSNOTIFY_EVENT_FILE, NULL, 0);
253 }
254 
255 /*
256  * fsnotify_xattr - extended attributes were changed
257  */
258 static inline void fsnotify_xattr(struct dentry *dentry)
259 {
260 	struct inode *inode = dentry->d_inode;
261 	__u32 mask = FS_ATTRIB;
262 
263 	if (S_ISDIR(inode->i_mode))
264 		mask |= FS_IN_ISDIR;
265 
266 	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
267 
268 	fsnotify_parent(dentry, mask);
269 	fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
270 }
271 
272 /*
273  * fsnotify_change - notify_change event.  file was modified and/or metadata
274  * was changed.
275  */
276 static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
277 {
278 	struct inode *inode = dentry->d_inode;
279 	__u32 mask = 0;
280 
281 	if (ia_valid & ATTR_UID)
282 		mask |= FS_ATTRIB;
283 	if (ia_valid & ATTR_GID)
284 		mask |= FS_ATTRIB;
285 	if (ia_valid & ATTR_SIZE)
286 		mask |= FS_MODIFY;
287 
288 	/* both times implies a utime(s) call */
289 	if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
290 		mask |= FS_ATTRIB;
291 	else if (ia_valid & ATTR_ATIME)
292 		mask |= FS_ACCESS;
293 	else if (ia_valid & ATTR_MTIME)
294 		mask |= FS_MODIFY;
295 
296 	if (ia_valid & ATTR_MODE)
297 		mask |= FS_ATTRIB;
298 
299 	if (mask) {
300 		if (S_ISDIR(inode->i_mode))
301 			mask |= FS_IN_ISDIR;
302 		inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
303 
304 		fsnotify_parent(dentry, mask);
305 		fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
306 	}
307 }
308 
309 #if defined(CONFIG_INOTIFY) || defined(CONFIG_FSNOTIFY)	/* notify helpers */
310 
311 /*
312  * fsnotify_oldname_init - save off the old filename before we change it
313  */
314 static inline const char *fsnotify_oldname_init(const char *name)
315 {
316 	return kstrdup(name, GFP_KERNEL);
317 }
318 
319 /*
320  * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
321  */
322 static inline void fsnotify_oldname_free(const char *old_name)
323 {
324 	kfree(old_name);
325 }
326 
327 #else	/* CONFIG_INOTIFY || CONFIG_FSNOTIFY */
328 
329 static inline const char *fsnotify_oldname_init(const char *name)
330 {
331 	return NULL;
332 }
333 
334 static inline void fsnotify_oldname_free(const char *old_name)
335 {
336 }
337 
338 #endif	/* ! CONFIG_INOTIFY */
339 
340 #endif	/* _LINUX_FS_NOTIFY_H */
341